1. Field of the Invention
This invention relates to a method for producing a liquid-jet head for jetting a liquid. More particularly, the invention relates to a method for producing an ink-jet recording head for ejecting ink as a liquid.
2. Description of the Related Art
Among ink-jet recording heads, as liquid-jet heads, there is, for example, one comprising:
a passage-forming substrate which has, formed therein, pressure generating chambers communicating with nozzle orifices, and a communicating portion communicating with the pressure generating chambers; piezoelectric elements formed on one surface of the passage-forming substrate; and a reservoir forming plate bonded to the surface of the passage-forming substrate where the piezoelectric elements are located, and having a reservoir portion constituting a part of a reservoir together with the communicating portion, and
wherein the reservoir portion and the communicating portion are brought into communication via a penetrated portion penetrating a vibration plate and a lamination film provided on the vibration plate to form the reservoir (see, for example, Japanese Patent Application Laid-Open No. 2003-159801 (FIGS. 7 to 8); hereinafter referred to as Patent Document 1). Concretely, portions of the vibration plate and the lamination film, which are opposed to the communicating portion (reservoir portion), are mechanically punched to form the penetrated portion for establishing communication between the reservoir portion and the communicating portion.
However, the formation of the penetrated portion by such mechanical processing poses the problem that foreign matter, such as processing swarf, occurs and enters the passages such as the pressure generating chambers, causing trouble such as ejection failure. After formation of the penetrated portion, cleaning, for example, is performed, whereby the foreign matter such as processing swarf can be removed to some degree, but is difficult to be removed completely. Mechanical processing for creation of the penetrated portion also involves the problem that cracks occur around the penetrated portion, thereby resulting in ejection failure. That is, if ink is filled in the presence of the cracks and ejected through the nozzle orifices, flakes come off the cracked sites, and clog the nozzle orifices, causing ejection failure.
The above-mentioned Patent Document 1 discloses a structure, in which a coating film comprising a resin material fixes the lamination film for preventing the occurrence of foreign matter, in an attempt to solve the above-described problems. The adoption of this structure may suppress the occurrence of foreign matter to some extent, but poses difficulty in completely preventing ejection failure due to foreign matter.
Within the so formed passages, such as the reservoir,a protective film comprising a material having ink resistance is generally formed in order to protect the passage-forming substrate, etc. from erosion by ink. If such a protective film is formed in the above-mentioned structure provided with the coating film, the protective film is placed on the coating film. The protective film formed on the coating film comprising the resin material has poor adhesion to the resin material. Thus, the protective film is apt to peel off, and the peelings are likely to clog the nozzles.
Such problems are present not only in a method for producing an ink-jet recording head for ejecting ink, but also in a method for producing other liquid-jet head for ejecting a liquid other than ink.